Typical art disclosing modular link belts with removable plugs or clips that occlude headless pivot rods journalled in module link end apertures comprise the following U.S. Pat. Nos.: 4,709,807 to N. J. Poerink, Dec. 1, 1987; 5,024,321 to J. M. Lapeyre, Jun. 18, 1991; 5,096,053 to W. G. Hodlewsky, Mar. 17, 1992; 5,217,110 to M. L. Spangler, et al., Jun. 8, 1993; 5,247,789 to G. Abbestam, et al., Sept. 28, 1993; 5,293,989 to C. Garbagnati, Mar. 15, 1994; 5,305,869 to P. E. Damkjaer, Apr. 26, 1994; 5,335,768 to T. J. Schladweiler, Aug. 9, 1994; and 5,435,435 to H. Chiba, et al., Jul. 25, 1995.
All of these have the common problem and deficiency in that the plugs, clips and the like, which hold the pivot rods in place, can work themselves loose under working conditions encountered in the operation of a conveyor belt. This catastrophically results in rods migrating out of the belts, causing total or partial breakage and possible contamination of carried products or fouling of the equipment. This problem is particularly evident in plastic belts with modular links that have some resiliency and which inherently have slick surfaces. Conditions that lead to such failures are particularly apt to be encountered in operation conditions, such as: regions of vibration, changing load weight patterns, regions of heavy or rapidly varying belt tension, and possible physical interfering items that may extend into the path of the belt, particularly at the belt edges.
It is the objective of this invention to solve that problem and to introduce improved novel structure for more reliably retaining headless pivot rods in place during the working life of conveyor belts with little likelihood of catastrophic failure or loss of plugs during normal belt working conditions.